Grinding tool speed reducer



Jan. 12, 1943. J BLAZEK ETAL 2,308,352

GRINDING TOOL SPEED REDUCER Filed March 11, 1940 25 INVENTORSr JoH/v Y.ELAZEK ATTORNEYS,

BY G/LEERrZ'ISL-AR Patented Jan. 12, 1943 GRINDING TOOL SPEED REDUCERvJohn Y. Blazek, Bedford, and Gilbert E. Sears, Cleveland, Ohio,assignorsto Lempco Products, Inc., Bedford, Ohio, a corporation ofOhioApplication March 11, 1940, Serial No. 323,260

4 Claims.

This invention relates, as indicated, to a grinding tool speed reducer,and has reference more particularly to a speed reducer adapted for usein conjunction with a crankshaft grinding tool of the type comprising asplit ring-like member having abrasive material along the innerperiphery thereof, which member is adapted for rotation about acrankshaft pin. Such grinding tools are well known in the art and areparticularly disclosed in United States Patent No. 2,179,465, issuedNovember 7, 1939, and invented by John Y, Blazek and United StatesPatent No. 2,171,- 417, issued August 29, 1939, and invented byMcGovern, et al.

In grinding crankshafts with a tool of the character described, it hasbeen found that with any given motor or source of power a satisfactoryfinish could be produced on crankshaft pins of diameters only within acertain limited range. A crankshaft grinding tool of the characterdescribed, to be commercially successful, must be capable ofaccommodating a vast range of crank pin diameters many of which areoutside of the said limited range. One of the virtues of such acrankshaft grinding tool is that its use does not necessitate theremoval of the crankshaft from the engine and it follows that certainspace limi-s tations must be observed. Such space limitations defeat anyattempt to utilize large driving pulleys.

The primary object of this invention has been to provide a speed reducerof the character described, which, when attached to a motor, is capableof imparting various peripheral speeds to the grinding tool.

Another object of this invention is to provide a device of the characterdescribed which can be quickly and easily inserted in the drivingmechanism, and which is compact, simple in mechanical features, andeconomical to manufacture.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawing, forming part of this specification, and inwhich like numerals are employed to designate like parts throughout thesame, Fig. 1 is a fragmentary side elevation of a device embodying thisinvention mounted on a crankshaft; Fig. 2 is a front elevation of Fig.1; Fig. 3 is a view partly in elevation and partly in section takensubstantially along the line 3-3 of Fig. 2, and Fig. 4 is a view similarto Fig, 1, but showing a modification thereof.

Referring more particularly to Figs. 1 and 2,

there is suitably mounted upon a frame or base plate 5 a motor or sourceof power 6, and a speed reducer embodying this invention indicatedgenerally by reference numeral 8. A belt ll] links together the speedreducer and the grinding tool indicated generally by reference numeralI2, the latter being illustrated in grinding position upon a crankshaft.I

As is seen in Fig. 2, the grinding tool in general comprises a splitring-like pulley made up of two semi-circular members l5 which, by meansof links I! and removable pins l8, form a substantially continuouspulley. Abrading material is suitably carried along the inner periphery20 of each of the members l5. It is thus seen that actuation of thesource of power rotates the grinding tool and abrades the crank pin. Thegrinding tool per se forms no part of this invention, and consequentlywill not be further described. Referring now to Fig. 3, a detaileddescription of the speed reducer follows: Suitably secured to the plate5, as by means of bolts 25, is a housing 26 which is sealed by a coverplate 21 secured thereto by bolts 28. Rotatably supported at one end bythe housing 26 is a shaft 30, which for coupling purposes is providedwith an axial bore for the reception of a driving shaft 3| of the sourceof power 6, the said shafts being drivingly interconnected by suitablemeans, such as a set screw 32. The shaft 30 is further provided withgear teeth 34, which mesh with a gear 35, the latter being supported inamanner to be presently described.

Suitably supported, parallel to the shaft 30, at one end by the housingand at the other end by the cover, is a shaft 31 upon which is suitablyrotatably mounted a pinion 38. This pinion is provided with an axialannular projection 39 upon which is mounted said gear 35. The pinion 38and gear 35 are locked against relative rotation by means of a key 40,and locked against relative axial movement by means of a set screw 4 I Agear 45, which meshes with the pinion 38,

is rotatably supported by the cover 21 and is provided with an axialprojection 46, upon which is mounted a large pulley 47, the gear 45 andpulley 41 being locked together by suitable means, such as a key 50. Theother end 5| of the shaft 30 is of reduced diameter and has securedthereto by suitable means, such as a key 52 a smaller pulley 53.Suitable anti-friction and spacing means, such as a washer 55, may beprovided.

It is understood that pulleys 4'! and 53 may take the form ofsprocket-wheels in which event a chain would be utilized in lieu of thebelt 10;

and that pulleys 41 and 53 may take the form of gears in which event theouter periphery of the grinding tool l2 would take the form of a gearand suitable gearing would connect pulleys 41 and 53 with the grindingtool l2.

From the foregoing description, it will be apparent that the smallerpulley 53 is directly driven by the source of power and that the largerpulley 4'! is, by means of gears 45, 38, 35 and 34, indirectly driven bythe source of power. It will also be seen that the relative peripheralor angular velocity of the smaller pulley 53 and the larger pulley 41 isa function of the reducingratio of the gear train. We have found thatby. proper selection of the gear train ratio, and diameters of thepulleys 53 and 4! and of the grinding toolv l2, the same source of powerand grinding tool can be utilized to produce a satisfactory-finish uponan increased variety of crank pin diameters and also upon an increasedvariation in the de gree of crank pin hardness. The harder and largerthe crank pin the fewer the R. P. M. required to produce a satisfactoryfinish so that with a given grinding tool and source of power, thehardness and diameter of the crank pin to beground will determine whichof the pulleys 53 or 41 is to be utilized.

Since all that is needed to change thespeed of the grinding tool is toswitch the belt from one pulley to the other, the change may be quicklyand easily accomplished. Alignment of the speed reducer with the motoris facilitated by the insertion of shaft 3| into the axial bore of shaft30. Installation is rendered rapid by manipulation of set screw 32 andbolt 25. The housing 26, being no higher nor wider than the source ofpower, is extremely compact. Due to the simplicity of the mechanism,manufacture is economical.

In the alternative illustrated in Fig. 4, the

speed reducer 8, instead of being secured to, the l plate 5, has securedthereto an arm 60, which, when the reducer tends to rotate in eitherdirection contacts the plate '5 and limits such rotation. The solesupport for the reducer is the shaft 3!.

It is to be understood that the forms of our invention, herewith shownand described, are to be taken as preferred examples of the sameand thatvarious changes in arrangement of parts may be resorted to withoutdeparting from the spirit of our invention nor the scope of thesubjoined claims.

Having thus described our invention, weclaim:

1. In a speed reducer a housing comprisingtwo elements, a gear having anaxial projection and an axial bore, said projection being journalled inone of said elements, a pulley keyed to said projection exteriorly ofsaid housing, a shaft one end of which is journalled in the other ofsaid elements and the other end of which is journalled in saidaxial boreand projects exteriorly thereof, a pulley keyed to said last-namedprojection, a gear in mesh with said first-named gear rotatablysupported by said housing and having an axial projection, a gearnon-rotatably secured to said last-named projection and a gear driven bysaid shaft in mesh with said last-named gear.

2. A drive unit comprising in combination a source of power, a shaftrotatably driven thereby, a rotatable housing, a pair of members eachadapted for conveying energy to a tool, gearing means within saidhousing for driving each of said members at a different speed, one ofthe elements of said means having an axial bore for accommodating saidshaft, means for drivingly connecting said first-named means and saidshaft, said shaft being the sole support for said housing, and means forlimiting rotation of said housing.

3. In a speedreducer, a housing, a gear member interiorly of saidhousing, a pulley member exteriorly of said housing, one of said membersbeing provided with a projection journalled to said housing and theother of said members being driven by said projection, said memberhaving said projection being provided with an axial bore, a shaft"journalled to said housing and to said bore and extending beyond saidprojection, a pulley driven by one end of said shaft, the other end ofsaid shaft being provided with an axial bore for coupling purposes, saidshaft having gear teeth thereon, and reduction gearing interconnectingsaid gear teeth and saidgear member whereby actuation of said shaftactuates said,

pulley member and said pulleys simultaneously at different angularvelocities.

4. A drive unit comprising a source of power,

a shaft rotatably driven thereby, the housing rotatable relatively tosaid shaft, a pair ofmembers each adapted for conveying energy to atool, means withinsaid housing and driven by said shaft for driving oneof said. members at one speedand for simultaneously driving another ofsaid members at another speed, said shaft being the sole support forsaid housing, and means for limitingrotation of said housing.

JOHN Y. BLAZEK.

GILBERT E. SEARS.

